Fluid Transfer Coupler
Mechanical and Fluid Systems
Fluid Transfer Coupler (GSC-TOPS-285)
A fluid coupler with a low overall alignment, low insertion forces, and a locking mechanism designed for use in satellite servicing
Overview
A fluid coupling is a hydrodynamic or hydrokinetic device used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch. It also has widespread application in marine and industrial machine drives, where variable speed operation and controlled start-up without shock loading of the power transmission system is essential. A fluid coupling consists of a housing and two turbines, plus the hydraulic fluid. The housing contains the fluid and turbines. The hydraulic fluid is directed by a pump whose shape forces the flow in the direction of the output turbine. The motion of the fluid is effectively toroidal. The Fluid Transfer Coupler addresses trades between ball-in-grove type couplers and pivoting pawls, along with various types of seals.
The Technology
The Fluid Transfer Coupler has a compensatory mechanism for alignment. All alignment is achieved within the coupler and alignment features are removed from the actuator. The coupler has a launch lock, which engages features on the coupler body and requires a hard
connection to the actuator body or the bracket. The gimbal has a clamshell spherical bearing between the lock collar and the radial bearing collar. It has larger clearances than a typical bearing of this type. This joint can potentially be eliminated if a lock is implemented. The thrust bearing allows and limits free movement. Marcel expander springs keep retainers centered, keeps the coupling centered, and prevents chatter. A hard stop limits ball loads under pressure. Wavy washer keeps ball bearings under enough pressure to prevent chatter. The alignment bell has a passive coupler which engages to align. The materials and coatings can be chosen to preclude galling and particle generation.
An active poppet seal provides debris seal at the nose and pressure seal further back. A passive poppet seal is provided by the seal cover to provide double duty. Various types of seals can be used, such as O-rings, spring-energized seals, and solid seals.

Benefits
- Minimizes alignment forces
- Minimizes wear
- Minimizes particle generation
Applications
- Satellite servicing
- Hydraulic connectors
- Telerobotics
Similar Results

Flow Control Devices
Both oscillators are flow control devices based on novel geometric designs. They have no moving parts and produce spatially oscillating jets. Each was designed to address a particular limitation of current oscillators.
Gaining control authority by decoupling frequency and amplitude:
Existing oscillators are limited in that the frequency of oscillation is controlled by input pressure or mass flow rate--the frequency and amplitude (mass flow rate) are coupled, limiting control authority over the oscillators. The new oscillator design decouples the frequency from the amplitude by employing a novel design featuring a main oscillator that controls the amplitude and a small oscillator that controls the frequency of the oscillations (see Figure 1). The decoupled oscillator delivers high (or low) mass flow rates without changing the frequency and vice versa.
Gaining control authority by synchronizing the entire oscillator jet array:
Existing oscillators in an array oscillate randomly. While this is useful for mixing enhancement, synchronized flow may be more beneficial for active flow control applications. The simple design of the new Langley synchronized oscillator achieves synchronization without having electro/mechanical or any other moving parts. The new oscillator enables synchronization of an entire array by properly designing the feedback loops to have one unique feedback signal to each actuator. Once each actuator has the same feedback signal, each main jet attaches to one side of the Coanda surface at the same time, allowing synchronized oscillation, as shown in Figure 2.

Fluid Structure Coupling Technology
FSC is a passive technology that can operate in different modes to control vibration:
Harmonic absorber mode: The fluid can be leveraged to act like a classic harmonic absorber to control low-frequency vibrations. This mode leverages already existing system mass to decouple a structural resonance from a discrete frequency forcing function or to provide a highly damped dead zone for responses across a frequency range.
Shell mode: The FSC device can couple itself into the shell mode and act as an additional spring in a series, making the entire system appear dynamically softer and reducing the frequency of the shell mode. This ability to control the mode without having to make changes to the primary structure enables the primary structure to retain its load-carrying capability.
Tuned mass damper mode: A small modification to a geometric feature allows the device to act like an optimized, classic tuned mass damper.

Micro scale electro hydrodynamic (EHD) modular cartridge pump
NASA GSFCs EHD pump uses electric fields to move a dielectric fluid coolant in a thermal loop to dissipate heat generated by electrical components with a low power system. The pump has only a few key components and no moving parts, increasing the simplicity and robustness of the system. In addition, the lightweight pump consumes very little power during operation and is modular in nature. The pump design takes a modular approach to the pumping sections by means of an electrically insulating cartridge casing that houses the high voltage and ground electrodes along with spacers that act as both an insulator and flow channel for the dielectric fluid. The external electrical connections are accomplished by means of commercially available pin and jack assemblies that are configurable for a variety of application interfaces. It can be sized to work with small electric components or lab-on-a-chip devices and multiple pumps can be placed in line for pumping greater distances or used as a feeder system for smaller downstream pumps. All this is done as a one-piece construction consolidating an assembly of 21 components over previous iterations.

Robotic System for Infra-structure Reconnaissance
The robotic system is comprised of six main components: the orb that performs the reconnaissance, an orb injector housing that attaches to a piping network, a tether and reel subsystem that attaches to the back of the injector housing, a fluid injection subsystem that attaches toward the front of the injector housing, an external power and data subsystem, and associated control and monitoring software.
Usage of the system begins with an operator attaching the injector housing, with the orb stowed inside, to a flanged gate valve belonging to the piping network of concern. Requisite power, data, and fluid subsystems are attached, and the system is energized for usage. The orb is released via the tether and reel, and a controlled fluid force is imparted on the orb to help guide it along its mission. The tether supplies power and guidance to the orb, and relays real-time data back to the operator.
The orb’s interior features a modular plug-and-play architecture which may comprise COTS instrumentation for reconnaissance or investiga-tion, LIDAR, and inertial measuring and motion sensors. This instru-mentation could be used in combination with other sub-systems such as lighting, and core and sample retrieving mechanisms. These com-ponents are supported by other onboard devices such as a CPU, power source and controller, and data transmission encoders and multiplexers.
The Robotic System for Infrastructure Reconnaissance is at TRL 8 (actual system completed and "flight qualified" through test and demonstration), and is now available for licensing. Please note that NASA does not manufacture products itself for commercial sale.

Variable-Aperture Reciprocating Reed (VARR) Valve
The VARR valve has been designed to provide a variable-size aperture that proportionately changes in relation to gas flow demand. When the pressure delta between two chambers is low, the effective aperture cross-sectional area is small, while at high delta pressure the effective aperture cross-sectional area is large. This variable aperture prevents overly restricted gas flow. As shown in the drawing below, gas flow through the VARR valve is not one way. Gas flow can traverse through the device in a back-and-forth reversing flow manner or be used in a single flow direction manner. The contour shapes and spacing can be set to create a linear delta pressure vs. flow rate or other pressure functions not enabled by current standard orifices. Also, the device can be tuned to operate as a flow meter over an extremely large flow range as compared to fixed-orifice meters. As a meter, the device is capable of matching or exceeding the turbine meter ratio of 150:1 without possessing the many mechanical failure modes associated with turbine bearings, blades, and friction, etc.